Fuse construction



May.16, 1939- w. o. SCHULTZ 2,158,633

FUSE. CONSTRUCTION Filed July 23, 1937 2 Sheets-Sheet l INVENTOR. W/lZM/V 0, 5 (W1 72 ATTORNEY.

May 1 6, 1939- w. of. SCHULTZ 2,158,638

v FUSE CONSTRUCTION Filed July 23, 1957 2 Sheets-Sheet 2 v INVENTOR. l V/zz/M 0 Jcwzrz Patented May 16. 1939 UNITED STATES PATENT OFFICE FUSE CONSTRUCTION Application July 23, 1937, Serial No. 155,205

19 Claims.

This invention relates to a fuse construction.

Objects of this invention are to provide a simple type of fuse construction which may be used in any capacity but which is eminently suitable as a fuse construction for association with a transformer or other electrical device.

This invention is intended to provide a fuse construction which is particularly useful on a single bushing transformer as these transformers have come into quite general use for rural service. These transformers are provided with only one primary bushing, the other side of the primary winding being solidly grounded to the transformer case.

Objects of this invention are to provide a fuse construction in which the fuse structure is carried by or supported from the transformer, in which an expulsion fuse is so mounted that the expelled gases and metallic vapors are expelled in a direction such that they will not strike the transformer casing, for example in which the gases are expelled in a horizontal plane spaced from the transformer casing.

Further objects-are to provide a fuse construction in which anexpulsion fuse tube is employed and in which a switch blade is released by mechanism restrained by the fuse link so that the switch blade, which is biased towards open positiqp, moves to open position upon blowing of the fuse, thereby providing a large gap in the circuit,

' preferably the switch blade being connected to the live side of the line so that the fuse assembly is disconnected from the line upon the blowing of the fuse and may thereafter be readily re- 5 moved and refused without any danger whatsoever to the lineman.

In greater detail, objects of this invention are to provide a fuse construction in which two spaced terminals are provided, preferably one above the 49 other, and are carried by suitable insulators so that a unitary structure is provided and may be supported directly, if desired, from a single bushing of a transformer, the fuse tube being mounted upon the lower of the two terminal members 45 and being very simply temporarily interlocked or held by such terminal member so that the fuse tube, though resisting the upward pull of the switch arm, nevertheless cannot be detached therefrom due to the force exerted by the switch 00 am. as means are provided which cause an interlock between the fuse tube and the lower of V the two terminals while the fuse tube is in its operative or service position.

Further objects are to provide a construction 55 such that after the fuse has blown and the switch (El, 200-114l arm has moved to its switch open position, the fuse tube may be rocked about a pivot pin upon which it is carried and may be rocked out of interlocking relation to the terminal member upon which the fuse tube is supported, so that the fuse 5 tube may be readily lifted from the pivot pin and may be refused while it is detached from the rest of the apparatus, and after refusing may be again placed on the pivot pin and rocked back into interlocking relation, the switch arm being pulled l0 downwardly and snapping into locking engagement with the fuse link releasing mechanism, the construction permitting the use of a simple switch stick to reposition the switch arm.

An embodiment of the invention is shown in 1d the accompanying drawings, in which:

Figure l is a side elevation, with parts broken away and in section, showing the position of the switch arm in full lines when it is in closed circuit position, and showing the switch arm in 20 dotted lines when it is in open position. 7 Figure 2 is a horizontal sectional view through a portion of the fuse tube and a portion of the intermediate contact member and through the switch arm.

Figure 3 is a fragmentary side elevation of the structure shown in Figure 1 taken at right angles to Figure 1.

Figure 4 is a sectional view on the line 4-4 of Figure 1. 30

Figure 51s a fragmentary View showing a modifled form of construction.

Referring to the drawings, it will be seen that the metal casing of the transformer is indicated by the reference character I and the insulating bushing by the reference character 2. This bushing carries an upper metallic cap 3 in the usual manner to.which one side of the primary of the transformer is attached. This cap 3, as may be seen most clearly from Figures 2 and 3, forms a 0 portion of the intermediate terminal member and is preferably integrally formed with a laterally extending arm 4 which terminates in an upper overhanging portion 5. This. intermediate contact formed with the members 3, 4 and 5 is also provided with a rigid pivot pin 6 which projects upwardly and which is adapted to receive and support the fuse assembly.

The fuse assembly comprises the insulating fuse tube 1 which is carried by a contact arm 8 provided with a hub portion 9 pivoted upon the pin 6 and freely removable therefrom when the fuse tube is rocked clear of the overhanging portion 5, see Figure 3. However, under normal conditions, the fuse assembly is in the position shown in Figures 1, 2 and 3, and the arm 8 ofisets or spaces the fuse tube '11 from the pivot pin ti so that when the fuse assembly is rocked into po= sition, a portion of the fuse tube is beneath the overhangingpart 5, see Figure 3, of the intermediate contact and consequently the fuse assembly is in interlocking relation when in this position with this intermediate contact. It is preferable to provide a small shoulder or stop Ml on the intermediate contact, see Figure 2, to limit the rocking motion of the fuse tube.

The fuse assembly includes the arm 8 and the fuse tube V. Preferably the arm 8 receives the end of the fuse tube V, as shown in Figure 2, and is provided with a cap l l which clamps the head of the fuse link in the usual manner. The fuse link may comprise a reduced fusible section l2 and a leader H3. The fuse tube projects outwardly from the supporting structure and is provided with an upwardly projecting arm it upon which is pivoted the lever it, such lever being formed of two spaced arms located on opposite sides of the pivot supporting arm M and having a lower bridge piece it which carries the threaded stud ll and the thumb nut if; for clamping the leader H3 in place.

The upper end of the arms forming the lever it are joined by a latch member it which, in the position normally occupied as shown in Figure 1, has a downwardly slanting upper face and a somewhat rounded lower end acting as a latch for the switch arm, as will be described. The arm M is also provided with a projecting lug 20, see Figure 1, which acts as a stop to limit the rocking motion of the lever it when it is released by the blowing of the fuse link.

A second insulator 20, see Figures 1 and 3, is supported from the intermediate contact or terminal member and projects upwardly and is provided with an upper terminal member which may include the connector receiving portion 522 to which the live side of the line is attached. This upper terminal member may also include a downwardly projecting spark finger 23 spaced from the lower spark finger 2d extending upwardly from the casing i, see Figure 1, to thus form a spark gap.

An upwardly biased switch arm 25 is secured to the upper terminal member and may comprise a flat spring member which is provided with acurved portion 2t and with a downwardly extending portion 2'17 terminating in an inwardly directed hooked end Ell normally engaging bu neath the latch portion 69 of the fuse link controlled lever.

The form of the invention shown in Figure 5 is like that previously described except the switch arm 25' need not have the depressed portion for the reception of the switch stick. Instead the straight portion 27! thereof may carry a switch stick receiving eyelet 29.

In the operation of the device, when the fuse blows, it is obvious that the fuse link releases the lever it, which, under the influence of the upwarldy biased switch arm, is rocked to releasing position, and thereafter the switch arm 25 moves upwardly into its switch open position, as shown .in dotted lines in Figure 1.

The live side of the line is now disconnected from the fuse assembly and the fuse assembly may be rocked about the pivot pin 6 out of interlocking relation with the intermediate terminal member and may be lifted bodily upwardly from the pin it and refused. Thereafter it is repositioned by merely rocking it back into the arsaeas position shown in Figures '1, 2 and 3, and the hooked end of the switch stick is positioned over the depressed portion 26 of the switch arm and the switch arm pulled downwardly until the hook 28 thereof locks beneath the latch member I9 of the fuse link controlled mechanism.

It is to be noted that the upward pull of the switch arm cannot detach the fuse assembly from the supporting or pivot pin, for while the fuse assembly is in operative position, it is also in interlocking relation with the intermediate terminal member.

It will be seen that a very simple, serviceable, and easily operated construction has been provided in which the automatic release of the mechanism occurs upon rupture of the fuse link, in which the expulsion fuse discharges the metallic vapors and gases in a horizontal plane above the transformer casing out of contact therewith, and in which the switch arm may be formed in a very simple manner. It is obvious that the switch arm 25 may have a depressed portion 26, as shown in Figure 1, or may have an eyelet 29, as shown in Figure 5, for the reception of a switch stick sothat after refusing the switch arm may be pulled downwardly by the switch stick into switch closing position in engagement with the latching mechanism.

It will be seen further that the construction lends itself readily to use with a single bushing transformer, though obviously the invention is not limited to this particular type of use.

Although this invention has been described in I considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. In a fuse construction for an electrical device having a metal casing, an insulating bushing i supported from said casing and having a terminal, a second insulator supported from said terminal and having a second terminal adapted to be connected to a line wire, a fuse assembly supported from the first mentioned terminal and projecting therefrom and including a fuse tube and a fuse link having one end connected to said first mentioned terminal, and a switch biased towards open position and carried by said second terminal and normally restrained from opening by said fuse link, said switch normally connecting said second terminal and the other end of said fuse link.

2. In a fuse construction an insulator having a terminal, a second insulator carried by said terminal and having a second terminal, a fuse assembly supported from said first mentioned terminal and projecting outwardly and including a fuse tube and a fuse link and latching mechanism normally restrained by said fuse link, and a switch arm supported by said second insulator and having one end electrically connected to said and having one end electrically connected to said second terminal and-having a free end normally .held in switch-closed position by said latching mentioned terminal.

4, In a fuse construction, insulating means having spaced terminals constituting a first terminal and a second terminal, a fuse assembly supported from said first terminal and projecting therefrom, said fuse assembly including a fuse tube and a fuse link having its inner end connected to said first terminal, and a switch arm extending from said second terminal to adjacent said fuse tube and electrically connected to-the outer end of said fuse link, said switch arm being biased towards motion away from said fuse tube and being restrained against motion by said fuse link.

5. In a fuse construction, insulating means having spaced terminals constituting a first terminal and a second terminal, a fuse assembly supported from said first terminal and projecting therefrom, said fuse assembly including a fuse tube and a fuse link having its inner end connected to said first terminal, said fuse tube having an open end and the outer end of said fuse link projecting from the open end .of said fuse tube, and a switch arm extending from said second terminal to adjacent the open end of said fuse tube and electrically connected to the outer end of said fuse link, said switch arm being biased towards motion away from said fuse tube and being restrained against motion by said fuse link.

6. In a fuse construction, insulating means having a first terminal and a second terminal arranged in spaced relation, a fuse tube having one end adjacent said first terminal and being supported from said first terminal, a fuse link within said fuse tube having its inner end electrically connected to said first terminal, latch means positioned adjacent the outer end of said fuse tube, and a switch arm supported from said second terminal and having a free end normally detachably engaged by said latch means, said switch arm being biased for motionaway from said latch means and said latch means being electricallyconnected to the outer end of said fuse link and being restrained against releasing motion by said fuse link.

'7. In a fuse construction, insulating means having a first terminal and a second terminal arranged in spaced relation, a fuse tube having one end interlocked with said first terminal and supported from said first terminal and projecting therefrom, a fuse link within said fuse tube having its inner end electrically connected to said first terminal, latch means carried by the outer end of the fuse tube and connected to the outer end of the fuse link, and a switch arm supported from said second terminal and biased towards switch open position, said switch arm being normally held by said latch means in switch closed position.-

8. In a fuse construction, insulating means ,having a first terminal and a second terminal arranged in spaced relation, a fuse tube, said first terminal including means for supporting said fuse tube and means for receiving said fuse tube in interlocking relation when said fuse tube is in its operative position, said fuse tube being movable on the supporting means out of interlocking relation with said first terminal, said fuse tube projecting outwardly from said first terminal, and having an outer end spaced from said first terminal, a fuse link within said fuse tube having its inner end electrically connected to said first terminal, latch means carried by the outer end of the fuse tube and connected to the outer end of the fuse link, and a switch arm supported from said second terminal and biased towards switch open position, said switch arm being normally held by said latch means in switch closed position.

9. In a fuse construction, an electrical device having a metallic casing, an insulating bushing carried by said casing and having a terminal adjacent its outer end and constituting a first terminal, an insulator carried by said first terminal and having a terminal at its outer end constituting a second terminal, a fuse tube removably supported from said first terminal and projecting outwardly therefrom and having an outer end spaced from said first terminal, a fuse link within said fuse tube, and a switch arm biased towards switch open position carried by said second terminal and electrically connected to and held in switch closed position by said fuse linkv 10. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal, insulating means for supporting said terminals, said first terminal having a pivot pin, a fuse tube having means fitting over said pivot pin and supported from said first terminal and projecting outwardly therefrom, a fuse link within said fuse tube, and a switch arm carried by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch arm and said first terminal, said switch arm being biased towards motion away from said fuse tube, and being restrained from motion by said fuse link.

11. In a fuse construction, a pair of terminals constituting a first terminal and a second termi-. nal, insulating means for supporting said terminals, a fuse assembly pivotally supported by saidfirst terminal and projecting outwardly therefrom, interlocking means between said first terminal and said fuse assembly, said fuse assembly when rocked about the pivot support being freed of the interlocking with said first terminal and being freely removable from said first terminal, said fuse assembly including a fuse tube and a fuse link, and a switch arm carried by said sec-- ond terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch arm and said first terminal, said switch arm being biased towards motionaway from said fuse tube, and being restrained from motion by said fuse link.

12. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal, insulating means for supporting said terminals, a fuse assembly pivotally supported from said first terminal and projecting outwardly therefrom, said first terminal having means overhanging said fuse assembly when said fuse assembly is in operative position and preventing removal of said fuse assembly, said fuse being movable about the pivot support from beneath the overhanging means to clear the overhanging means and permit free removal of said fuse assembly, said fuse assembly including a fuse tube tube and a fuse link, and a switch arm carried an a fuse link, and a switch arm carried by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch arm and said first terminal, said switch arm being biased towards motion away from said fuse tube, and being restrained from motion by said fuse link.

13. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal, insulating means for supporting said terminals, a fuse assembly pivotally supported by said first terminal and projecting outwardly there from, interlocking means between said first terminal and said fuse assembly, said fuse assembly when rocked about the pivot support being freed of the interlocking with said first terminal and being freely removable from said first terminal, said fuse assembly including a fuse tube and a fuse link, and aswitch arm supported from said insulating means and having one end electrically connected to said second terminal and having a .free end normally located near the outer end of said fuse tube, said fuse link normally connecting said switch arm and said first terminal, said switch arm being biased towards motion away from said fuse tube and being restrained from motion by said fuse link, said switch arm moving in a plane at substantially right angles to the plane in which said fuse assembly is movable.

14. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal located above said first terminal, insulating means for supporting said terminals, said first terminal having pivot means, a fuse tube having means cooperating with said pivot means and supported from said first terminal and projecting horizontally outwardly therefrom, a fuse link within said fuse tube, and a switch arm carried by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch armand said-first terminal, said switch arm being biased towards motion away from said fuse tube in a plane substantially at right angles about the plane in which said fuse tube is movable, said switch arm being restrained from motion by said fuse link.

15. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal, insulating means for supporting said terminals, a fuse assembly supported from said first terminal and projecting outwardly therefrom, pivotal means joining said fuse assembly to said first terminal, said fuse assembly being adapted to be rocked in a horizontal plane about said pivotal means, interlocking means between said first terminal and said fuse assembly, said fuse assembly when rocked about said pivotal means being free from the interlocking with said first terminal and being freely removable from said first terminal, said fuse assembly including a fuse by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch arm and said first terminal. said switch arm being biased towards motion away from said fuse tube in a substantially vertical plane and being restrained from motion by said fuse link.

16. In a fuse construction, a pair of erminals constituting a first terminal and a second terminal, insulating means for supporting said terminals, a fuse assembly supported from said first terminal and projecting outwardly therefrom, pivotal means connecting said fuse assembly and said first terminal, said first terminal having means overhanging said fuse assembly when said fuse assembly is in operative position and preventing removal of said fuse assembly, said fuse assembly being adapted to be rocked about said pivotal means in a horizontal plane to clear said overhanging means and permit free removal of said fuse assembly, and a switch arm carried by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting .said switch arm and said first terminal, said switch arm being biased towards motion away from said fuse tube in a substantially vertical plane and being restrained from motion by said fuse link.

17. In a fuse construction, a pair of terminals constituting a first terminal and a second terminal, insulating means for supporting saidterminals, a fuse assembly supported from said first terminal and projecting outwardly therefrom, pivotal means connecting said fuse assembly and said first term nal, said first terminal having means overhanging said fuse assembly when said fuse assembly is in operative position and preventing removal of said fuse assembly, said fuse assembly being adapted to be rocked about said pivotal means in a horizontal plane to clear said overhanging means and permit free removal of said fuse assembly, and a switch arm carried by said second terminal and having a free end normally located near the outer end of said fuse tube, said fuse link normally electrically connecting said switch arm and said first terminal, said switch arm being biased upwardly towards motion away from said fuse tube in a substantially vertical plane and being restrained from motion by said fuse link.

18. In a fuse construction, an insulating support including a relatively fixed terminal and a movable terminal member, said movable terminal member having a circuit closing position and being biased to open circuit position, a fuse tube removably interlocked with the fixed terminal at one end, a latch on the other end of said tube, a fuse link in said tube normally holding said latch in operative position, said movable terminal member being normally held by said latch to close a circuit through said fuse link.

19. In a fuse construction a pair of spaced terminals, a fuse assembly supported from one of said terminals and projecting outwardly and in cluding a fuse tube and a fuse link and latching mechanism normally restrained by said fuse link, and a switch arm electrically connected to the other of said terminals and having a free end normally held in switch closed position by said latching mechanism and engaging said latching mechanism. said switch arm being biased towards switch open position away from said latching mechanism, said switch arm having means for the reception of a switch stick, whereby upon refusing said switch arm may be pulled by the switch stick into latching engage ment with said latching mechanism.

WILLIAM O. SCHULTZ. 

